The present invention relates to a governor valve. It is known, in pressure fluid operated tools, to arrange, in different ways, a governor comprising a piston which is movable in two opposed directions to open and to close, respectively, a supply channel for pressure fluid which leads to a drive chamber and a drive mechanism arranged in the tool.
The present invention aims at arranging, particularly in smaller, long and narrow pressure fluid operated tools, such as a pressure fluid operated engraving pen, a governor valve having a movable piston extending transversally through the housing of the tool and having the advantages that, for one thin, it can be located easily accessible for the fingers of the operator during operation of the tool, and for another thing, that it protrudes only slightly from the tool housing through which it extends and will therefore not be unwieldy and spoil the appearance of the tool. As the piston is only required to perform small movements, it is possible to use the device in accordance with the invention also in narrow toolsxe2x80x94such as, for example, an engraving penxe2x80x94the housings of which have a small thickness of the walls through which the piston extends and therefore have little room for movements of seal rings fitted on the piston without these rings coming outside the walls. These advantages have been obtained with the device in accordance with the present invention.
The governor valve device in accordance with the invention is described in closer detail below, with reference to the attached drawing, which shows a pressure fluid operated engraving pen provided with said device. The device can also be used in other types of pressure fluid operated tools and devices and be varied in its design within the scope of the Claims; the illustrated embodiment of the invention constituting, therefore, only an example of one of several possible applications of the invention.